adr for conceptual view

docs/adrs/00002-analysis-graph.md

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+# 00002. Analysis graph API in Trustify
+
+Date: 2025-01-23
+
+## Status
+
+ACCEPTED
+
+## Context
+
+This ADR is an addenda to [previous ADR](00001-graph-analytics.md) as an attempt to clarify the differences between the graph
+relationships we capture and the view we want to create from the forest of graphs.
+
+Ingesting an sbom captures a set of trustify relationships, which are instantiated
+in the forest of graphs as;
+
+```mermaid
+graph TD
+    PackageA -->|CONTAINS| PackageOther
+    PackageD -->|CONTAINED_BY| PackageA
+    PackageA -->|DEPENDS_ON| PackageB
+    PackageB -->|DEPENDENCY_OF| PackageA
+    SBOMDOC1 -->|DESCRIBES| PackageA
+    UpstreamComponent -->|ANCESTOR_OF| PackageA
+    image.arch1 -->|VARIANT_OF| ImageIndex1
+    image.arch2 -->|VARIANT_OF| ImageIndex1
+    SBOMDOC2 -->|DESCRIBES| ImageIndex1
+
+    SBOMDOC3 -->|DESCRIBES| srpm_component
+    binarycomponent1 -->|GENERATED_FROM| srpm_component
+    binarycomponent2 -->|GENERATED_FROM| srpm_component
+```
+
+Trustify relationships attempt to put an abstraction over relationships 
+defined by any format of sbom (eg. cyclonedx, spdx). 
+
+This graph encapsulates provenance of sbom relationship though end users are unlikely 
+to directly navigate such graphs, as it would mean forcing concrete understanding of relationship directionality. 
+If we were to _normalise_ all relationships (similar to the rewrite of all CONTAINS into CONTAINED_BY) the 
+resultant DAG is probably ok ex. we could rewrite the following relationships:
+
+  [ _binarycomponent1_ **GENERATED_FROM** _srpm_component_] to [_srpm_component_ **GENERATES** _binarycomponent1_]
+
+  [ _image.arch2_ **VARIANT_OF** _ImageIndex1_] to [_ImageIndex1_ **VARIANTS** _image.arch2_]
+
+So while we make the logical model easier to comprehend it is a good practice to keep logical model separate and not try to overload that model to serve as conceptual model.
+
+The `api/v2/analysis` endpoints are responsible for building up the conceptual view. Where we want to query, filter and
+traverse on the following.
+
+```mermaid
+graph TD
+    SBOMDOC1 -->|DESCRIBES| PackageA
+    PackageA -->|CONTAINS| PackageOther
+    PackageA -->|CONTAINS| PackageD
+    PackageA -->|DEPENDS| PackageB
+    
+    SBOMDOC2 -->|DESCRIBES| ImageIndex1
+    UpstreamComponent -->|ANCESTOR_OF| PackageA
+    ImageIndex1 -->|VARIANTS| image.arch1
+    ImageIndex1 -->|VARIANTS| image.arch2
+
+    SBOMDOC3 -->|DESCRIBES| srpm_component
+    srpm_component -->|GENERATES| binarycomponent1
+    srpm_component -->|GENERATES| binarycomponent2
+```
+
+It is a feature that this conceptual model spans beyond traversal of just transitive software dependencies.  
+
+For example, searching for any node in above view, should let us traverse ancestors and descendents ... a 
+few illustrative examples:
+
+**Search for 'PackageA'**
+* component ancestors would be `[UpstreamComponent]`
+* component descendents would be the tree underneath 'PackageA' `[PackageOther,PackageD,PackageB]`
+
+**Search for 'image.arch1'**
+* component ancestors would be `[ImageIndex1]`
+* component descendents would be `[]`
+
+_Note: every node in the graph already knows its relationship to original SBOM so no need
+to enumerate DESCRIBES relationship ... though in the future we may see other artifacts (eg. sbom) 
+DESCRIBES._
+
+We should make it easy to visualise this conceptual model direct from the endpoints (ex. Accept: image/svg 
+would pull down an svg representation).
+
+## Decision
+
+### Implement `api/v2/analysis/component`
+
+payload returns immediate ancestor/descendent relations (eg. 'one deep')
+```json
+{
+  "sbom_id": "",
+  "node_id": "",
+  "purl": [
+    ""
+  ],
+  "cpe": [],
+  "name": "PackageA",
+  "version": "",
+  "published": "2024-12-19 18:04:12+00",
+  "document_id": "urn:uuid:537c8dc3-6f66-3cac-b504-cc5fb0a09ece",
+  "product_name": "",
+  "product_version": "",
+  "ancestor": [
+    {
+      "sbom_id": "",
+      "node_id": "",
+      "relationship": "AncestorOf",
+      "purl": [
+        ""
+      ],
+      "cpe": [],
+      "name": "UpstreamPackage",
+      "version": ""
+    }
+  ],
+  "descendent": [
+    { 
+      "sbom_id": "",
+      "node_id": "",
+      "relationship": "Variants",
+      "purl": [
+        ""
+      ],
+      "cpe": [],
+      "name": "PackageC",
+      "version": ""
+    }
+  ]
+}
+}
+```
+
+Where items in `ancestor` array imply _Ancestor component_ VIEWRELATION _Searched component_ ... in the above example that would 
+mean _UpstreamPackage_ **AncestorOf** _PackageA_
+
+Where items in `descendent` array imply _Searched component_ VIEWRELATION _Descendent component_ ... in the above example that would
+mean _PackageA_ **Variants** _PackageC_
+
+This endpoint provides the following url params with the following defaults
+- anc_depth=1
+- desc_depth=1
+- relationshipType=*
+
+### Implement `api/v2/analysis/ancestor`
+  payload returns all ancestor relations
+```json
+{
+  "sbom_id": "",
+  "node_id": "",
+  "purl": [
+    ""
+  ],
+  "cpe": [],
+  "name": "",
+  "version": "",
+  "published": "2024-12-19 18:04:12+00",
+  "document_id": "urn:uuid:537c8dc3-6f66-3cac-b504-cc5fb0a09ece",
+  "product_name": "",
+  "product_version": "",
+  "ancestor": [
+    {
+      "sbom_id": "",
+      "node_id": "",
+      "relationship": "AncestorOf",
+      "purl": [
+        ""
+      ],
+      "cpe": [],
+      "name": "",
+      "version": ""
+    }, {} ....
+  ]
+}
+```
+
+The `ancestor` array contains a list of ancestors with the last item
+in the list being considered the _root component_.
+
+This is equiv to
+- anc_depth=*
+- desc_depth=0
+- relationshipType=*
+
+### Implement `api/v2/analysis/descendent`
+returns all descendent relations
+```json
+{
+  "sbom_id": "",
+  "node_id": "",
+  "purl": [
+    ""
+  ],
+  "cpe": [],
+  "name": "",
+  "version": "",
+  "published": "2024-12-19 18:04:12+00",
+  "document_id": "urn:uuid:537c8dc3-6f66-3cac-b504-cc5fb0a09ece",
+  "product_name": "",
+  "product_version": "",
+  "descendent": [
+    {
+      "sbom_id": "",
+      "node_id": "",
+      "relationship": "Variants",
+      "purl": [
+        ""
+      ],
+      "cpe": [],
+      "name": "",
+      "version": "",
+      "descendent": [{} ....]
+    }, {} ....
+  ]
+}
+```
+The `descendent` array contains a list of descendents with each component also containing any nested descendents.
+
+This is equiv to
+- anc_depth=0
+- desc_depth*
+- relationshipType=*
+
+### Implement `api/v2/analysis/relationship`
+
+Provide an experimental interface using relationship view.
+
+TBA
+
+### Implement visualisation
+
+Generation of a high quality svg
+Generation of mermaid represenation
+
+### Document analysis graph API
+
+Openapi definitions should provide good REST API level documentation.
+
+Additional sections should be added to docs/book 
+
+## Alternative approaches
+
+**Directly use graphs:** It is likely that we will provide raw interface to the graphs (aka `api/v2/analysis/relationship`) though
+we do not want to move responsibility of building up the 'view' to a client so still need to provide the other endpoints for that.
+
+**Build a new graph representing the conceptual model:** As graphs do not mutate, its not so far fetched to
+consider additionally generating a conceptual graph. It might be something we consider as an optimisation in 
+the future though for now thinking it would be good to avoid the cost (ram, memory). The conceptual graph model might be 
+considered a replacement for logical model though that would be flawed thinking as we always need the logical 
+model to tell us relationship provenance eg. the logical model is absolutely required.
+
+## Consequences
+
+* We need to identify all the relationships that are candidates for rewrites into DAG (ex. DEPENDENCY_OF to DEPENDS_ON)
+* Having a clear conceptual model will reduce cognitive load of having to mentally reparse graph relations
+* A DAG based conceptual model means we can also do neat stuff like generate visual representations (mermaid, svg, etc)
+* In the future we can have a graphql interface directly on the graph.
+* Cache invalidation, partitioning and general memory use will need some deeper thought - in the recent past
+we have discussed the use of LRU on the graph hashmap which probably addresses any immediate need.